Wireless LAN Experiments

Wireless LAN Experiments
Computer Network Experiments
NBL Assisting Session for CIS, NCTU
Lecturer: Elia Chen 陳世揚, Project Manager
Network Benchmarking Laboratory
Outline
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About Wireless LAN
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Recent Features of WLAN
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Introduction to Wireless LAN
Variant Wireless LAN Technologies
b/g-Mixed Mode Compatibility
Wi-Fi Protected Access (WPA) Support
Proprietary Throughput Improvement
The Experiment Approach
Test Utility Adopted
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Introduction to NetIQ Chariot
Add Pair and Select the Script
Run and Get the Throughput
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Outline (cont.)
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Experiments in Brief
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Test Coverage for Students in NBL
Parameters Configuration (constant conditions)
Functionality Tests
Interoperability Tests
Performance Test
Test Methodology Design
Copyright © 2004 ITRI-NCTU NBL, All rights reserved
The author, Elia Chen, has unconditionally permitted Prof. Yingdar Lin and his teaching
assistant to properly modify these slides to be used in the courses of future semesters.
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About Wireless LAN
Introduction to the WLAN
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One MAC supporting multiple PHYs
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PHY: FH, DS, IR, CCK, PBCC, and OFDM (more in the future!)
MAC: CSMA/CA (collision avoidance) with optional “Point Coordination”
Two configurations
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“Independent” IBSS (Ad Hoc) and “Infrastructure” BSS
From: © IEEE, “Tutorial of Draft Standard 802.11/D3.0”
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About Wireless LAN
Variant WLAN Technologies
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Features of 802.11b, 802.11g, and 802.11a technologies
From: © Broadcom, “The New Mainstream Wireless LAN Standard”
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Recent Features of WLAN
b/g-Mixed Mode Compatibility
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802.11g AP, Mixed Client
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802.11b AP, 802.11g Client
From: © Broadcom, “The New Mainstream Wireless LAN Standard”
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Recent Features of WLAN
Wi-Fi Protected Access (WPA) Support
RADIUS
Supplicant
WEP (x)
802.1X over
TKIP
RADIUS
Agent
EAP-TLS
RADIUS
Server
From: © Wi-Fi Alliance, “Overview of Wi-Fi Protected Access”
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Recent Features of WLAN
Proprietary Throughput Improvement
Atheros Super A/G
108 Mbps (60Mbps in Real)
TI Turbo Mode (G+)
90 Mbps (35 Mbps in Real)
Broadcom 125 High Speed Mode Boost of 35% (30~35 Mbps in Real)
Agere’s new chipset
150 Mbps?
From: © Atheros Communications, “802.11 Wireless LAN Performance”
& Wi-Fi Planet News, “Wi-Fi Marketing's Favorite Numbers“
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The Experiment Approach
A Testing Equals An Experiment?
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You can find some examples of network product testing
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An experiment is
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"a scientific test which is done in order to discover what happens to
something in particular conditions.“ by Collins COBUILD Dictionary
While correctly designed, it ALWAYS consists of
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Tests done and published in some famous Magazines?
Wi-Fi Interoperability Test in the Agilent Lab?
exactly ONE control factor related to your hypothesis
other constant conditions specified as complete as possible
大膽假設 小心求證
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Test Utility Adopted
Introduction to NetIQ Chariot
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There is an end-to-end solution Chariot, which tests
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NetIQ Chariot
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Wireless LAN (Chariot is convenient, and especially, specified by Wi-Fi)
Any other network device operates with TCP/IP
“evaluates the performance of networked applications on devices”
“is used to optimize your network and predict the impact of changes”
工欲善其事
必先利其器
Access
Point
Station
From: © NetIQ,, “User Guide of Chariot”
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Test Utility Adopted
Add Pair and Select the Script
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Test Utility Adopted
Run and Get the Throughput
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Experiments in Brief
Test Coverage for Students in NBL
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6 tests designed for students in NBL (at MIRC 604)
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Tests cover Functionality, Interoperability, and Performance
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Test Name
Subject
Time
FT-1
Functionality Test 1
Basic Settings
60 min
FT-2
Functionality Test 2
Security Modes
FT-2x The Extension of Functionality Test 2
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IT-1
Interoperability Test 1 - Wi-Fi Style
(see later)
IT-2
Interoperability Test 2
b/g Mixed Mode
PT-1
Performance Test 1
Throughput vs. Chipset
60 min
30 min
Used Platform (Operating System)
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Station (Client): Windows XP Professional with WPA Support
Server: Windows Server 2003, Standard Edition running CA, IAS, IIS
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Experiments in Brief
Parameters Configuration (constant conditions)
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Settings for AP under test (APUT) and STA under test (STAUT)
APUT Settings
IP Address
192.168.3.11 /24
Operation Mode
Infrastructure
Wireless Mode
802.11b/g Auto
SSID
‘NBL’
Channel
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Wireless Security
Disable
[Other Settings]
[Default]
STAUT Settings IP Address
192.168.3.21 /24
Link and Signal Monitor Enable
Power Save
Disable
[Other Settings]
[Same as APUT or Default]
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Experiments in Brief
Functionality Test 1 (FT-1)
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Hypothesis: Functions of wireless mode and channel are correct
Utility: Ping; Chariot with ‘InquiryL’ script for 30 sec
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Control Factor for both APUT and STAUT
1 Wireless Mode {802.11b/g Auto, 802.11g Turbo, 802.11b Only}
2 Channel
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{1, 6, 11}
Observations if…
1 Associations occur
2 Good or Excellent status by Link and Signal Monitor indicated
3 Replies of ping from STAUT to Server received
4 ‘InquiryL’ completes without any error
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Experiments in Brief
Functionality Test 2 (FT-2)
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Hypothesis: Functions of security mode are correct
Utility: Ping; Chariot with ‘InquiryL’ script for 30 sec
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Control Factor for both APUT and STAUT
Security Level
1 WEP Key
0x9876543210
2 WPA PSK PassPhrase Random ASCII of Length = {15, 31}
3 WPA EAP-TLS
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Observations if…
1 Associations occur
2 Good or Excellent status by Link and Signal Monitor indicated
3 Replies of ping from STAUT to Server received
4 ‘InquiryL’ completes without any error
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Experiments in Brief
The Extension of Functionality Test 2 (FT-2x)
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Hypothesis: Functions of security mode are correct
Utility: Ping; Chariot with ‘InquiryL’ script for 30 sec
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This test uses a different version of driver for STAUT
The control factor and observations are the same as FT-2
Please be careful that if any thing occurs unexpectedly, do not modify
the configurations of Windows XP before noticing Elia (me).
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Experiments in Brief
Interoperability Test 1 - Wi-Fi Style (IT-1)
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Data Transfer # means using 1: ‘FileSndL’ Downsteam, 2: ‘FileSndL’
Upstream, and 3: ‘InquiryL’ Downstream respectively
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Experiments in Brief
Interoperability Test 2 (IT-2)
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Hypothesis: BSS in mixed mode will operates correct, but the
throughput in mixed mode will lower than in pure mode
Utility: Ping; Chariot with ‘InquiryL’ and ‘FileSndL’, both for 30 sec
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Control Factor in the BSS
Another Involved STA {802.11b device, 802.11g device, not exists}
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Observations
1 Associations occur
2 Good or Excellent status by Link and Signal Monitor indicated
3 Replies of ping from STAUT to Server received
4 ‘InquiryL’ completes without any error
5 Average Throughput of ‘FileSndL’
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Experiments in Brief
Performance Test 1 (PT-1)
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Hypothesis: The throughput of different chipset may differ obviously
Utility: Ping; Chariot with ‘high_performance_throughput’ for 60 sec
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Actually this test is a performance benchmarking
Control Factor
AP-STA Pair of Different Chipset {Broadcom BCM94306,TI TNETW1130}
with best transmission rate settings
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Observations
1 Associations occur
2 Replies of ping from STAUT to Server received
3 Average Throughput of ‘high_performance_throughput’
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Test Methodology Design
Especially for Graduate Students
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The left period of 30 minutes is for you to discuss with Elia
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A good methodology which possibly
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Define a new test methodology
If you can, perform the new test in NBL
follows the experiment principle (scientific view)
reflects the issues in WLAN technology and industry (technical view)
expends properly low cost (operational view)
最後, 請大家別全都選了 WLAN 實驗, 還可考慮
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Network Security
Routing and Bridging
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